What Is a Blood Test Tube? Types, Colors & Their Meaning

Have you ever been asked by your doctor to go through a blood examination? If so, then you must be familiar with the blood test tubes used to collect and hold the blood sample. These glass or plastic-based test tubes contain chemicals that do not allow the blood to coagulate and, therefore, ease testing. As these blood test tubes come in various colors and types, selecting the right product can sometimes be challenging.

In this article, let us address what blood test tubes are and why are they used in laboratories. In addition, some of the well-known blood test tube brands have also been linked for the reader’s convenience.

What is a Blood Test Tube?

A blood test tube, also known as a blood collection tube, is a specialized medical product that is used to hold and store the blood sample until the time of testing. These are constructed using glass or medical-grade plastic (mostly polyethylene terephthalate or PET) and come with rubber closures of different colors for easy identification.

This is important as different blood test tubes have different types of additives in them such as EDTA, heparin, citrate, etc. which are needed for different purposes. Some of these prevent the clotting of the blood sample while others are required for conducting different tests.

Blood Test Tubes: Types, Colors, and Meanings

The blood test tubes used in healthcare facilities come with pre-filled additives of different natures. This is because all of these additives serve distinct purposes. Each of these tubes is identified based on the color of the closure. Therefore, the following table enlists the type of closures for the blood test tubes along with their additives, mode of action, as well as uses:

Closure Type	Additive	Mode of Action	Uses
Red	None	Blood gets clotted and serum separates	Immunology, serology, blood banks
Gold	None	Serum separator tube (SST) has a gel at the bottom to separate serum and blood upon centrifugation	Chemistries, immunology, serology
Light Green	Plasma separating tube (PST) with lithium heparin	Anticoagulation due to lithium heparin, the plasma gets separated with PST gel at the tube bottom	Chemistries
Purple	EDTA (Ethylene diamine tetraacetic acid)	Forms calcium salts to remove calcium	Blood bank (crossmatch), and hematology (CBC), require full draw-invert 8 times so that clotting and platelet clumping is prevented
Light Blue	Sodium citrate	Forms calcium salts to remove calcium	Coagulation tests including protime and prothrombin time, full draw is required
Green	Sodium heparin or lithium heparin with or without gel	Inactivates thrombin and thromboplastin	Sodium heparin is suitable for lithium and ammonia levels while lithium heparin is used for ammonia levels only, suitable for stats and routine chemistry
Dark Blue	EDTA	The tube has no contaminating metals	Toxicology, trace element testing of zinc, copper, lead, mercury
Light Gray	Sodium fluoride and sodium or potassium oxalate	Antiglycolytic agent preserves glucose for up to 5 days	Glucoses, require a full draw as a short draw may cause hemolysis, suitable for lactic acid and blood alcohol determination
Yellow	Acid-citrate-dextrose (ACT)	Complement inactivation	HLA tissue typing, DNA studies, paternity testing
Yellow-Black	Broth mixture	Preserve the viability of the microbes	In microbiology for aerobes, anaerobes, fungi
Black	Sodium citrate (buffered)	Forms calcium salts to remove calcium	Westergren Sedimentation rate requires a full draw
Orange	Thrombin	Quickly clots blood	STAT serum chemistries
Light Brown	Sodium heparin or EDTA	Contains virtually no lead	Serum lead determination
Pink/Lavender	Potassium EDTA	Forms calcium salts	Immunohematology
White	Potassium EDTA	Forms calcium salts	Molecular/PCR and bDNA testing

Choosing the Right Blood Test Tubes

Apart from choosing the right type of blood test tube based on the information given in the table, some other factors also need to be considered. These include the following:

Sterility Requirements

If the test you want to run on the blood sample requires a sterile sample, make sure that the blood test tube selected for this purpose is sterile.

Compatibility of the Anticoagulant

Another important factor is to check if the anticoagulant present in the blood test tube is compatible with the experiments to be run on the blood sample.

Volume

The blood test tube chosen for collecting the blood sample should have enough volume capacity to hold the required blood sample.

Dimensions

The dimensions of the test tubes are a concern especially when they are to be placed on racks for the period before testing.

Rimed Design

If the test tubes have a rimmed design, pouring the sample becomes easy. However, blood test tubes are available in both rimmed as well as non-rimmed shapes.

Construction

Another factor to look into is the construction material used for the tubes. This is important because glass-based items are more prone to breakage but can be subjected to high-temperature ranges. In most cases, borosilicate glass is used for their construction.

As for the plastic-based blood test tubes, these do not pose the risk of breakage but can initiate a chemical reaction with the contents of the tube. Commonly used plastics for this purpose are polypropylene, polycarbonate, polystyrene, polyethylene (PET), as well as PMMA.

Shape

The blood test tubes also come in more than one shape. For example, blood test tubes with flat-bottom, round-bottom, as well as cone-bottom are available. Among these, the flat-bottom ones are used for clinical, industrial, medical, as well as environmental applications. Similarly, round-bottom tubes are often employed in healthcare and food processing labs.

As for the cone-bottom ones, these are ideal for refrigerating the samples or subjecting them to centrifugation. Their clarity as well as high mechanical strength makes them durable and easy to use. The graduations on the tubes also allow measurement of the sample volume.

Blood Test Tubes at Health Supply 770: Features and Specifications

Blood test tubes are also known as blood collection tubes or vacutainer tubes. These are the items that can hold and store a blood sample until testing is performed. The product is smaller in size and single-use item.

When it comes to learning about blood test tubes, it is also essential to look into some of the products that many brands manufacture. Some of these well-known brands are also available at Health Supply 770 and have been detailed below along with their features and purchase links:

BD 366430 Vacutainer Venous Blood Collection Tubes Serum Tubes

Price: $1,124.33 (Per case/1000 pieces)

Product Details

BD 366430 Vacutainer venous blood and serum collection tubes by BD Medical are the products that have been designed for basic blood examination. This is because these blood test tubes do not contain any additives and, therefore, can be used to temporarily hold and store the blood until a test is conducted.

Moreover, these BD 366430 Vacutainer venous blood and serum collection tubes are small in size and have the dimensions 16 x 100 mm. The color of the closure is red for easy identification. Furthermore, these closures are also coated with silicone to make it stronger and more fitted in place to ensure spill-proofing. In addition, the construction material of these BD 366430 vacutainer venous blood and serum collection tubes is glass that is durable and s

BD 367871 Medical Vacutainer Blood Collection Tubes

Price: $545.88 (Per case/1000 pieces)

Product Details

BD 367871 medical vacutainers are plastic-based vacutainer tubes that have freeze-dried sodium heparin as their additive in a concentration of 75 US units. These are employed to prevent the collected blood sample from clotting which makes them suitable for plasma determination.

The dimensions of these BD 367871 medical blood test tubes are 13 x 75 mm and each of these can hold a volume of up to 4 ml. Moreover, the tubes come with a label on them which can be used by the laboratory staff to mention the patient’s name as well as the test details.

Furthermore, the dark green Hemogard closures not only allow the quick identification of the tubes but also help prevent accidental sample spillage. In addition, the attachment of a double-ended needle is also easy to the tube. As these BD 367871 medical vacutainers are constructed using medical-grade plastic, these are tough and do not pose any risk of breakage.

BD 362800 Vacutainer PPT Venous Blood Collection Tube

Price: $2,806.00 (Per case/1000 pieces)

Product Details

BD 362800 vacutainers PPT venous blood collection tubes have K₂ EDTA as an additive. These are plastic-based blood test tubes that are sterile. Due to their clear appearance, it is easy to visualize the contents of the tube with the naked eye.

As for their dimensions, these BD 362800 vacutainers PPT venous blood collection tubes are 16 x 100 mm in size. Each of these tubes can hold up to 8.5 ml of the blood sample. Moreover, the presence of the white Hemogard closures reduces the risk of accidental spillage of the contents.

Furthermore, these BD 362800 vacutainers PPT venous blood collection tubes are used for conducting coagulation tests like prothrombin time (PT) as well as activated partial thromboplastin time (APTT).

BD 367884 Vacutainer Heparin Tubes

Price: $1,182.00 (Per case/1000 pieces)

Product Details

BD 367884 Vacutainer heparin tubes come with lithium heparin anticoagulant at a concentration of 75 USP units. The agent keeps the blood sample in liquid form so that the testing can be performed. The construction material of these blood test tubes is plastic which is strong and breakage-resistant.

Moreover, these BD 367884 vacutainer heparin tubes come with green-colored Hemogard closures. These are strong enough to protect the accidental sample spillage and, therefore, keep the laboratory staff protected from the contents of the tube. In addition, these BD 367884 vacutainer heparin tubes can also be subjected to centrifugation.

BD 367985 Vacutainer SST Tubes

Price: $1,682.00 (Per case/1000 pieces)

Product Details

BD 367985 Vacutainer SST tubes by BD Medical are used for the determination of serum. These are considered suitable for blood donor screening, the identification of infectious diseases, as well as the evaluation of blood chemistry.

Moreover, these BD 367985 Vacutainer SST tubes come with strong closures that are gold in color. The construction of the products is strong due to the use of medical-grade construction material. Furthermore, their manufacturing complies with the EPA guidelines.

*Note: The prices of these items mentioned in the article are taken from the Health Supply 770 website. These may vary over time.

The blood test tubes mentioned in this article, along with many other medical supplies, can be purchased from Health Supply 770, a reliable name when it comes to medical products. They have a 30-day money-back guarantee and provide your products to you in the shortest possible time. Click the link at the end of the article to check the wide range of medical and laboratory supplies.

Conclusion

Taking blood work is essential as it can reveal the inner state of a person’s body. To do so, blood sampling is required. These blood samples, when drawn, are prone to coagulation. Therefore, the addition of an anticoagulating agent is necessary. Similarly, other additives are also needed when the sample is taken for different purposes.

In this regard, the use of blood test tubes or vacutainer tubes is necessary. These vacutainer tubes come with pre-filled additives which differ depending upon the type of the tube. Blood samples are loaded into them which get mixed with the additives present in the product. As a result, the blood does not coagulate. In addition, the sample also gets prepared for further testing.

Considering their importance, blood test tubes should be kept in bulk in all healthcare facilities including hospitals, clinics, as well as veterinary facilities. For purchasing different types of blood test tubes, reliable vendors like Health Supply 770 should be approached. They ensure the provision of quality products along with satisfactory services.